Knight 100 Series, Руководство по обслуживанию

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2
Maintenance
(continued)
Test low water flow conditions
NOTICE
These tests are to be carried out
once the Knight Fire Tube boiler is
completely piped in with adequate gas
and water flow. Once the low water
cutoff test is completed, ensure that
the isolation valve is opened up to
allow full water flow.
Figure 2-3 Adjust outlet isolation valve
Test procedure - low water cutoff (LWCO)
1. Locate the pinhole button above the RESET button on
the display board. Insert a thin wire (such as a paper clip)
into the hole and press the button once and hold for 5
seconds to place the boiler into Service Mode. In Service
Mode the boiler will fire at ignition speed and will then
modulate up to full fire.
2. Allow the unit to progress through its normal diagnostics
and pre-purge programming.
3. Allow the unit to fire and operate until the temperatures
stabilize. This occurs when the inlet and outlet
temperatures are rising together and the Delta T (
△ T) is
maintained.
4. When the unit stabilizes, begin to slowly shut off the
isolation valve on the outlet piping of the boiler (see
FIG. 2-3). This will begin to restrict the flow and
simulate a low flow condition.
5. While slowly shutting off the isolation valve, refer to the
Status Screens to watch the behavior of the boiler. These
screens allow you to monitor the inlet temperature,
outlet temperature, and
△ T.
6. When the △ T reaches 55˚F (13°C), the control will
attempt to modulate the firing rate down to protect it
from low flow conditions.
7. When the △ T reaches 60°F (16°C), the control module
will turn off the burner. If the control module shuts
down, the test was successful.
8. Completely open the isolation valve on the outlet piping
of the boiler.
9. Resume operation.
NOTE: This lockout is a soft lockout. Once the △ T has
decreased to an acceptable level and there is a call for
heat, the unit will fire again to meet the demand.
37
Service Manual
Test procedure - manual reset high limit (MRHL)
1. Follow steps 1 - 3 in the low water cut off test procedure.
2. From the Status Screen, press the NAVIGATION dial to access
the Set Points Screen.
3. Press the LEFT SELECT [LIMITS] key.
4. Select the manual reset high limit (MRHL) by rotating and
pressing the NAVIGATION dial.
5. Decrease the set point of the MRHL to below the current outlet
temperature (or to its minimum setting, whichever is higher).
Press the RIGHT SELECT [SAVE] key.
6. Press the RIGHT SELECT [HOME] key. The new parameter
will upload to the control.
7. If the current outlet temperature is above the new MRHL set
point, the MRHL will function causing boiler lockout.
8. Repeat steps 2 - 7 to adjust the MRHL back to its normal
settings.
DIR #2000543632 00
ADJUST OUTLET
ISOLATION VALVE ONLY